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Full text of "The Cambridge Natural History"

vni                             BRAIN   OF   EDENTATES                            165
A subsequent study of the brain and of the muscles of these
animals has led to results not entirely in harmony with these
views.
Dr. Elliot Smith is of opinion,1 after an exhaustive study of
the Edentate brain, that in this region of the body the present
group shows veiy decided points of likeness to the Carnivora;
thafc is, so far as concerns the Anteaters. On the other hand,
Orycteropus is as distinctly comparable with a primitive Ungulate
type, such as is exemplified by Moschus. " If the brain of
Orycteropus" he remarks, " were given to an anatomist
acquainted with all the other variations of the mammalian
type of brain, there is probably only one feature which would
lead him to hesitate in describing it as an exceedingly simple
Ungulate brain. That one feature is the high degree of
inaerosinatism.2 Manis, on the other hand, does not come especially
near to Orycter&gns. The brain of Mdnis conforms to a simple
type of architecture, which agrees in many points with both those
of Qr-ycteropus and the American Edentates ; there is not sufficient
evidence to show which type it really favours/* Elliot Smith
would, in fact, agree with Max "Weber that it is better, if a
division is to be made, to divide the group into three orders:—
the Xenarthra (Sloths, Anteaters, and Armadillos), Tubulidentata
(Orycteropus), and Sqnamata (Mawis), instead of into Xenarthra
and !N"omarthra,
Messrs. Windle and Parsons8 axe disposed to see in muscular
similarities reasons for tmiting Manis with the American Edentates,
though they confess to being unable to place Oryeterop'us; in
this animal, they say, *c we are more struck by the generalised
mammalian arrangement of its muscles than by any special
Edentate characters. There are, however, two muscles in Ovyctcro-
p'us wliieh show peculiarities not found elsewhere than in the
Edentates " ;—the triceps, which has more than one scapular head,
and the tibialis postietts, which is double. They conclude that
Orycteropus " presents some feeble claims to be taken into the
order."
We shall here adopt the following divisions.
1   Trans. Mnn. Sec. (2) vii. 1898, p. 277.
2  «„«* large olfactory lobes.
3  Prae. Zo&l. Sec. 1899, p. 1014.